[3.19.y-ckt stable] Patch "3w-sas: fix command completion race" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Thu May 21 20:36:41 UTC 2015
This is a note to let you know that I have just added a patch titled
3w-sas: fix command completion race
to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue
This patch is scheduled to be released in version 3.19.8-ckt1.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 7d46d28f27f7763fc44ee92a4c553c5513715473 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch at lst.de>
Date: Thu, 23 Apr 2015 09:48:49 +0200
Subject: 3w-sas: fix command completion race
commit 579d69bc1fd56d5af5761969aa529d1d1c188300 upstream.
The 3w-sas driver needs to tear down the dma mappings before returning
the command to the midlayer, as there is no guarantee the sglist and
count are valid after that point. Also remove the dma mapping helpers
which have another inherent race due to the request_id index.
Signed-off-by: Christoph Hellwig <hch at lst.de>
Reported-by: Torsten Luettgert <ml-lkml at enda.eu>
Tested-by: Bernd Kardatzki <Bernd.Kardatzki at med.uni-tuebingen.de>
Acked-by: Adam Radford <aradford at gmail.com>
Signed-off-by: James Bottomley <JBottomley at Odin.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/scsi/3w-sas.c | 50 ++++++++++----------------------------------------
drivers/scsi/3w-sas.h | 4 ----
2 files changed, 10 insertions(+), 44 deletions(-)
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index 2361772..f837485 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -290,26 +290,6 @@ static int twl_post_command_packet(TW_Device_Extension *tw_dev, int request_id)
return 0;
} /* End twl_post_command_packet() */
-/* This function will perform a pci-dma mapping for a scatter gather list */
-static int twl_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
-{
- int use_sg;
- struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
- use_sg = scsi_dma_map(cmd);
- if (!use_sg)
- return 0;
- else if (use_sg < 0) {
- TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1, "Failed to map scatter gather list");
- return 0;
- }
-
- cmd->SCp.phase = TW_PHASE_SGLIST;
- cmd->SCp.have_data_in = use_sg;
-
- return use_sg;
-} /* End twl_map_scsi_sg_data() */
-
/* This function hands scsi cdb's to the firmware */
static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry_ISO *sglistarg)
{
@@ -357,8 +337,8 @@ static int twl_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
if (!sglistarg) {
/* Map sglist from scsi layer to cmd packet */
if (scsi_sg_count(srb)) {
- sg_count = twl_map_scsi_sg_data(tw_dev, request_id);
- if (sg_count == 0)
+ sg_count = scsi_dma_map(srb);
+ if (sg_count <= 0)
goto out;
scsi_for_each_sg(srb, sg, sg_count, i) {
@@ -1102,15 +1082,6 @@ out:
return retval;
} /* End twl_initialize_device_extension() */
-/* This function will perform a pci-dma unmap */
-static void twl_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
-{
- struct scsi_cmnd *cmd = tw_dev->srb[request_id];
-
- if (cmd->SCp.phase == TW_PHASE_SGLIST)
- scsi_dma_unmap(cmd);
-} /* End twl_unmap_scsi_data() */
-
/* This function will handle attention interrupts */
static int twl_handle_attention_interrupt(TW_Device_Extension *tw_dev)
{
@@ -1251,11 +1222,11 @@ static irqreturn_t twl_interrupt(int irq, void *dev_instance)
}
/* Now complete the io */
+ scsi_dma_unmap(cmd);
+ cmd->scsi_done(cmd);
tw_dev->state[request_id] = TW_S_COMPLETED;
twl_free_request_id(tw_dev, request_id);
tw_dev->posted_request_count--;
- tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
- twl_unmap_scsi_data(tw_dev, request_id);
}
/* Check for another response interrupt */
@@ -1400,10 +1371,12 @@ static int twl_reset_device_extension(TW_Device_Extension *tw_dev, int ioctl_res
if ((tw_dev->state[i] != TW_S_FINISHED) &&
(tw_dev->state[i] != TW_S_INITIAL) &&
(tw_dev->state[i] != TW_S_COMPLETED)) {
- if (tw_dev->srb[i]) {
- tw_dev->srb[i]->result = (DID_RESET << 16);
- tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
- twl_unmap_scsi_data(tw_dev, i);
+ struct scsi_cmnd *cmd = tw_dev->srb[i];
+
+ if (cmd) {
+ cmd->result = (DID_RESET << 16);
+ scsi_dma_unmap(cmd);
+ cmd->scsi_done(cmd);
}
}
}
@@ -1507,9 +1480,6 @@ static int twl_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
/* Save the scsi command for use by the ISR */
tw_dev->srb[request_id] = SCpnt;
- /* Initialize phase to zero */
- SCpnt->SCp.phase = TW_PHASE_INITIAL;
-
retval = twl_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
if (retval) {
tw_dev->state[request_id] = TW_S_COMPLETED;
diff --git a/drivers/scsi/3w-sas.h b/drivers/scsi/3w-sas.h
index d474892..fec6449 100644
--- a/drivers/scsi/3w-sas.h
+++ b/drivers/scsi/3w-sas.h
@@ -103,10 +103,6 @@ static char *twl_aen_severity_table[] =
#define TW_CURRENT_DRIVER_BUILD 0
#define TW_CURRENT_DRIVER_BRANCH 0
-/* Phase defines */
-#define TW_PHASE_INITIAL 0
-#define TW_PHASE_SGLIST 2
-
/* Misc defines */
#define TW_SECTOR_SIZE 512
#define TW_MAX_UNITS 32
--
1.9.1
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